Abstract:By using four different matrix alloys, such as ZL102, ZL114A, ZL205A and ZL301, as substrate, SiC_f/Al composite with volume fraction of 40% SiC_f were prepared by vacuum pressure impregnation. The interface characteristics and fracture morphology of SiC_f/Al composite were observed by TEM and SEM, and the tensile strength was tested. The results show that, the interfaces of continuous SiC_f/Al composite of different matrix alloys exist significant differences in their interface morphology, mechanical properties and fracture morphology. Among them, the SiC_f/ZL102 composite with tiny needle Al₄C₃ at the interface and without obvious interface layer, the interfacial bonding is weak, with average tensile strength of 615.7 MPa and obvious fracture fiber pull phenomenon. A large bulk of CuAl₂ and Al₄C₃ phase exist at the interface of the SiC_f/ZL205A composite, the interfacial bonding is strong, with average tensile strength of 385.1 MPa, and flush fracture. The interface of SiC_f/ZL114A composite is slightly stronger than that of SiC_f/ZL102 composite material, the average tensile strength is 475.9 MPa. The rod-like Al₄C₃ phase exists at the interface to SiC_f/ZL301 composite, a large number of Mg element enrichment reduces the interfacial reaction, the average tensile strength is 769.3 MPa, the fracture exists dimple, the matrix changes the direction of horizontal crack.

Key words: matrix alloy; SiC_f/Al composite; tensile strength; interface; vacuum pressure impregnation